Positive yarn feeding means for circular knitting machines



J. D. MOYER April 16, 1968 POSITIVE YARN FEEDING MEANS FOR CIRCULARKNITTING MACHINES 2 Sheets-Sheet 1.

Filed July 27, 1966 April 16, 1968 J. D. MOYER POSITIVE YARN FEEDINGMEANS FOR CIRCULAR KNITTING MACHINES 2 Sheets-Sheet 2 Filed July 27,1966 26 0 WWW/4 w w 8 2 0 m W w 4 H w W 4 United States Patent Ofi ice3,377,824 Patented Apr. 16, 1968 3,377,824 POSITIVE YARN FEEDING MEANSFOR CIRCULAR KNITTING MACHINES James D. Moyer, Wyomissing, Pa., assignorto Textile Machine Works, Wyomissing, Pa., a corporation of PennsylvaniaFiled July 27 1966, Ser. No. 568,191

9 Claims. (Cl. 66-132) ABSTRACT OF THE DISCLOSURE A positive yarn feeddevice for a circular knitting machine including a driven roller havingan inflatable sleeve about which yarn is passed from a source of supplyto the needles of the knitting machine. A sensing means is positionedintermediate the roller and knitting machine responsive to changes intension in the yarn for varying the circumference of the sleeve throughfluid control means to accordingly vary the rate of feed of the yarn tothe needles.

The instant invention relates to yarn feeding means and particularly tosuch means having the capability of delivering yarn .at substantiallyuniform tension to another mechanism such as the stitch forminginstrumentalities of a circular knitting machine.

Heretofore numerous types of yarn furnishing devices had been proposedcomprising rolls and the like and serving to positively draw the yarnfrom a yarn supply such as a pirn at the rate determined solely by thedrawing means itself and independently of variations in the drag of theyarn due to faulty winding of the pirn or other causes. In some of theprior devices provision has also been made to vary the speed at whichthe yarn is drawn in response to variations in the consumption of theyarn by the yarn using device such as a circular-knitting machine. Theprincipal object of the instant invention is the provision of a positivey-arn furnishing device of the latter type but which is more responsiveto changes in the demand for the yarn and otherwise exhibits advantagesover the known devices. Thus an object of the invention is the provisionof a yarn furnishing device by which the rate of delivery of the yarn tothe yarn using mechanism is substantially instantaneously responsive toeven minor changes in the tensions of the yarn such as are caused, forexample, by variations in its stretch characteristics.

More particularly an object of the invention is the provision of apositive yarn feeding device comprising a rotating body around which abight of the yarn is passed, the body being so constructed that itseffective yarn drawing circumference varies proportionately withvariations in the tension in the yarn being fed to the knittinginstrumentalities or other yarn using mechanisms. A further object ofthe invention is the provision of such device in which the rotating bodycomprises an inflatable sleeve and there is means to subject theinterior of the sleeve to more or less fluid pressure, whereby theeflective yarn drawing circumference of the sleeve increases ordecreases, under the control of means for sensing the tension in theyarn and hence the demand therefor.

More specifically a device embodying the instant invention includes theinflatable sleeve interposed between the yarn supply and the knittingmachine or other mechanism to which the yarn is to be delivered, thesleeve constituting a draw roll for the yarn, means to rotate the sleeveat predetermined speeds related to the speed of rotation of the knittingmachine or such other mechanism, means to. apply compressed air to theinterior of the sleeve to inflate the same, and valve means under thecontrol of a yarn tension sensing device to control the fluid pressureWithin the sleeve and the extent of inflation thereof and hence of itseffective circumference in performing its draw roll function.

The invention will be more fully understood and fur ther objects andadvantages thereof will become apparent when reference is made to themore detailed description which is to follow and to the accompanyingdrawings in which:

FIG. l'is an elevational view of the device of the instant inventionincorporated in the yarn furnishing means of a circular knittingmachine, the latter being illustrated diagrammatically;

FIG. 2 is a sectional view on an enlarged scale taken on the line 2-2 ofFIG. 1 looking in the direction indicated by the arrows;

FIG. 3 is a top plan view on an enlarged scale, and with parts insection, of the device as shown in FIG. 1;

FIG. 4 is a sectional view taken on the line 44 of FIG. 3 looking in thedirection indicated by the arrows;

FIG. 5 is a sectional view taken partially on the line 5-5 of FIG. 1looking in the direction indicate-d by the arrows and illustratingdiagrammatically a bight of yarn around the yarn drawing means of theinstant invention and its path of travel therefrom to the knittingmachine; and

FIG. 6 is a detail sectional view on an enlarged scale taken on the line66 of FIG. 3 looking in the direction indicated by the arrows.

Referring now to the drawings and more particularly to FIG. 1 a yarnfeeding device in accordance with the instant invention is illustratedat 10 in association with a circular knitting machine of the rotarycylinder type diagrammatically illustrated at 12. It will be understoodthat while the instant yarn feeding mechanism has found a principalfield of use in connection with circular knitting machines, particularlyhigh spced machines adapted for example, to knit .at a rate approachingone thousand courses per minute of plain knitted fabric, its use is notlimited and it can be employed and its advantages obtained with otheryarn using machines or devices. However t-he following description willbe directed to its association with a knitting machine such as thatdiagrammatically illustrated.

Knitting machine 12 has the usual needle cylinder 14 and associated camstructure (not shown) whereby y-arn Y fed to the needles (not shown)through a yarn feeding means of any suitable type is converted intoknitted fabric. The knitting machine also includes a yarn rack 17 havingmeans 18 of any suitable type for supporting one or more pirns 20, onebeing shown, of yarn Y. The

yarn .rack additionally includes ported by one or more pillars 23, onebeing shown, the superstructure carrying guide eyes 24 directing theyarn from the pirn to the device now to be described.

Referring now particularly to FIGS. 2 to 6 inclusive, device 10comprises -a tubular member or sleeve 26 having a lower threaded end 28threaded into a socket member 30 and maintained in adjusted positiontherein by a lock nut 31 (see FIG. 2). Socket member 30 is rigidlysecured in any suitable way to or made integral with a bracket 32 whichin turn is secured in fixed rigid relationship to a member 34 forming aportion of the machine frame. The lower' end of sleeve 26 (see FIG. 2)is internally recessed as at 36 to receive a ball bearing unit 38 whichrests on an annular flange 40 formedat the lower end of socket member30. Sleeve 26 (see FIG. 2) is also provided at its upper end with aninternal recess 42 supporting a ball bearing 'unit 44-. V

' An elongated tube 46 having a'central bore 47 and of smaller diameterthan sleeve 26 is mounted for rotation within the latter in ball bearingunits 38 and 44, tube 46 projecting above and below the tubular sleeve26. The lower projecting end of tube 46 carries a pulley 48 suitablyfixed to the tube for joint rotation therewith as by a set screw 50penetrating an integral collar 52. Pulley 48 is adapted to be driven torotate the tube 46 at a speed proportional to the rate of rotation ofneedle cylinder 14 as by a belt 54 connecting pulley 48 and a pulley 55comprising an annular member secured to needle cylinder 14 for rotationtherewith.

The end of tube 46 projecting below pulley 48 is mounted with a pressfit or is otherwise secured in the inner race of a ball bearing unit 56.A hollow block houses the lower end of tube 46, hearing 56 and a sealingwasher 64 of any suitable wear resistant mate-rial, such as a compressedfiber composition, on which the end of asuperstructure 22 sup-.-.

the tube rests. Set screws 66 on opposite sides of the block penetratethe same adjacent the upper end of bearing 56. The set screws arepointed as illustrated and are threaded into the block sufliciently thatthe inclined surfaces defined by the pointed ends press the bearing unit56 firmly against a flange 58 formed in block 60. The block is preventedfrom rotating with tube 46 in any suitable way as for example bycooperating abutments on the block and frame member 34. An airpassageway 68 leads from the outer annular wall of the block to thecentral opening of washer 64, the entrance end of the passageway beinginternally threaded to receive a correspondingly threaded end of aconnector 69 for a conduit 70 the latter leading from any suitablesource of fluid under pressure such as a compressed air source. The rateof flow of compressed air through conduit 70 is under the control of asuitable valve means such as manually operated needle valve 71.

Referring now particularly to FIGS. 1 and 2 a collar 72 is secured tosleeve 26 adjacent the upper end thereof, the collar having a projection74 to which one leg 76 of a U-shaped bracket 78 is secured as by studs77. An arm 80 is secured as by studs 79 to an upper leg 81 of bracket78, the arm adjacent the end remote from the bracket being recessed asat 82 to receive a ball bearing unit 84 in which an upper end portion 88of reduced diameter of tube 46 is mounted for rotation. A nozzle 86projects through a central opening 83 formed in the end wall of recess82 and is threaded or otherwise secured in the bore 47 of tube 46.

Referring now particularly to FIGS. 2, 3 and 4 a plate member 90 isfixed on arm 80 by screws 92 penetrating arcuate slots 94, a washer 96being interposed between the head of each screw and its associated slot,whereby the angular relationship of the plate member to arm 80 may bereadily adjusted. Spaced bosses 98 and 100* having opposed parallelsurfaces 99 and 101, respectively, project upwardly from plate member90, thebosses suitably being integral with the plate member. Nozzle 86previously mentioned extends through a perforation in the plate memberlocated between the bosses.

A valve member 102 comprising a plate having a lower flat surface ismounted for swinging movement on a horizontal pin 104, the pin beingreceived in a bearing 106 formed in a hub portion of the valve memberand the ends of the pin being secured in bosses 98 and 100. The mountingof valve member 102 is such that when its lower surface is in asubstantially horizontal plane it overlies and closes or substantiallycloses the orifice of nozzle 86 and when swung upwardly on its pivot pin104 opens the orifice for the emission of fluidsuchas compressed airtherefrom. Valve member 102 is urged to its orifice opening position bycompression spring 108.'A sensing means or tension arm 110 defining ayarn guide eye 116 has a hub portion 112 mounted for rotation with ashaft 114 the hub portion being secured'to the shaft byany suitablemeans such as a set screw 117. One end of shaft 114 is rotatablyreceived in a bearing 118 in boss 98. The opposite end of shaft 114 isrotatably received in an axially extending bearing formed' in acylindrical block 120 mounted for rotation in a cylindrical recess 122in boss 100. A pin 124 projects inwardly from block 120 and a similarpin 126 projects outwardly from hub portion 112. A coiled torsion spring127 (see FIG. 6) surrounds shaft 114 between block 120 and hub 112 andhas one end secured to pin 124 and its other end secured to pin 126 thespring being of a character to bias hub 112 and arm 110 to rotate in aclockwise direction as viewed in FIGS. 1, 4 and 6. Block 120 may bemanually rotated to adjust the bias of the spring to the desired valuein any suitable way such as by employing a pin 128 fixed thereto as ahandle, the block being secured in any adjusted position by tightening aset screw 130. Hub portion 112 of the tension arm carries a screw 132threaded therein, the screw having a downwardly projecting end portionpositioned to contact valve member 102 adjacent the end thereof remotefrom pivot pin 104. Screw 132 is adapted to be secured in any adjustedposition as by a lock nut 134.

Referring again to FIGS. 1 and 2 a thread draw-off device indicatedgenerally at 136 is mounted on tube 46 and between collar 72 and arm 80.The device comprises a cylindrical core 138 formed of any suitablematerial such as aluminum, a support plate 140 and an expandable sleeve144 having an inner annular surface surrounding but in nonadheredrelationship to core 138. Support plate 140 has a hub portion 146 whichis secured to tube 46 for rotation therewith as by set screw 148. Theperipheral surface of plate 140 is threaded to receive a correspondinglythreaded annular nut 150. Sleeve 144 is made of a resilient wearresistant material such as natural or artificial rubber, neoprene or thelike and has an approximately uniform wall thickness in the centralsection thereof the walls tapering to maximum thicknesses adjacent theends of the sleeve. The lower end of the sleeve defines a flange 152which is confined in fluid sealing relationship between support plate140 and a flange 154 of nut 150. The upper end'of sleeve 144 is definedby an inwardly directed flange 156 which is confined in fluid sealingrelationship between an annular shoulder 158 formed on core 138 and anut 142 threaded on a portion 160 of reduced diameter of the core. Tube46 at approximately the mid-point between the ends of sleeve 144 isprovided with at least one pair of opposed radially extendingpassageways 162 com municating with bore 47 and aligned with radiallyextending passageways 164 in core 138 whereby fluid under pressure ,inbore 47 is conducted to the inner surface of sleeve 144. While a singlediametrically opposed pair of the aligned passageways 162 and 164 havebeen found to be effective to inflate sleeve 144 additionalcorrespondingly aligned passageways may be employed if desired. Asmentioned above sleeve 144 is formed of rubber, neoprene or likestretchable resilient material, such material having the advantage, inaddition to those due to its stretchable resilient properties, ofproviding a nonslipping surface for a yarn drawn in a :bight therearoundas illustrated in FIG.

whereby upon each rotation of the sleeve a predeter-- mined length ofyarn is drawn from the pirn irrespective of variations in tension of theyarn between the sleeve and the pirn caused by imperfections in thewinding of the pirn or the like.

Base 166 of U-shaped bracket 78 support arms 168 and 170 at a heightcorresponding to the mid-point of the length of sleeve 144. Each of thearms 168 and 170 at their ends toward roll 136 carries a yarn guide eye172. Arms 168 and 170 are secured to base member 166 as by screws 174penetrating elongated slots in the arms and threaded into the basemember whereby the distance of the guide eyes from core 138 may beadjusted. An arm 176 is secured to rack 17, the arm defining a guide eye178 in the path of the yarn lbetween guide eye 116 of tension arm 110and the yarn feeding means of the knitting machine.

In preparation for the operation of the knitting machine incorporatingthe positive yarn feeding means of the instant invention the yarnleading from pirn is threaded through guide eyes 24 then through guideeye 172 of arm 168 in a bight around sleeve 144 thence through guide eye172 of arm 170. through guide'eye 116 of tension arm 110 and finallythrough guide eye 178 to the yar feeding means of the knitting machine.

The tension to be exerted by the tension arm on the yarn will vary withthe type of yarn. For example for nylon yarn of from fifteen to seventydenier the resistance of the tension arm to movement should be such thatapproximately a one gram pull is required at the guide eye 116 to rotatethe arm against the action of the spring. Hence the torsion of spring127 is adjusted to the desired value, as determined by the particularyarn employed, by rotating block 120 and securing the block in itsproperly rotated position by set screw 130. Plate member 90 is thenadjusted to position the guide eye 116 of tension arm 110 in thevertical plane of the travel of the yarn between guide eye 172 of arm170 and guide eye 178.

Following the above described adjustments the tension arm is manuallydepressed to cause screw 132 to hold valve member 102 closed against theorifice of nozzle 86, valve 71 is partially opened to admit fluid,suitably air, under pressure to the bore 47 of tube 46 and the knittingmachine is operated. The tension arm is then released and valve 71adjusted until the extent of inflation of sleeve 144 is such that it isdelivering the yarn at the rate demanded by the knittinginstrumentalities of the machine with the tension arm in an intermediateposition partially releasing, through the medium of valve member 102,the fluid pressure within the sleeve. Thereafter as the machinecontinues to operate, the sleeve, due to its nonslip surfacecharacteristics, positively delivers a given length of yarn on eachrotation. Furthermore any change in the demand for the yarn by theknitting instrumentalities and any change in the length of the yarnbetween the sleeve and the knitting instrumentalities resulting from thenormal variation in the stretch characteristics of the yarn, both ofwhich cause variations in the tension of the yarn, are substantiallyinstantaneously compensated for by the adjustment of the degree ofopening of valve member 102 and hence of the degree of inflation ofsleeve 144 and the length of its yarn drawing circumference,

The device of the instant invention, as described above, thus providesnot only for positive withdrawal of the yarn from the supply at apredetermined rate, which is not influenced by faulty winding of thesupply pirn or other such faults, but also for substantiallyinstantaneous response to the change of tension in the yarn as it is fedto the knitting instrumentalities. As a result a fabric of uniformstitch structure is produced.

Having thus described the invention in rather full detail, it will beunderstood that these details need not be strictly adhered to and thatvarious changes and modifications may be made all falling within thescope of the invention as defined by the swbjoined claims.

What is claimed is:

1. A device for positively delivering yarn from a supply thereof to ayarn using apparatus comprising a rotatable body having an annularlycontinuous yarn engaging surface, means for rotating said body, meansfor guiding yarn from said supply around said yarn engaging surface andto said yarn using apparatus, means engageable with said yarn betweensaid body and said apparatus for sensing the tension in the yarn, andmeans under the control of said sensing means for varying thecircumferential extent of said yarn engaging surface.

2. A device as defined in claim 1 wherein said rotatable body comprisesan inflatable element having an inner wall and said means for varyingthe circumferential extent of said yarn engaging surface comprises meansfor applying various fluid pressures to the inner wall of saidinflatable element to inflate the same to different extents.

3. A device as defined in claim 2 wherein said means for applyingvarious fluid pressures to the inner wall of said inflatable elementcomprises means defining a fluid passageway having an entrance and anexit, means for supplying fluid to said passageway through saidentrance, valve means at said exit for controlling the flow of fluidtherethrough, and means intermediate said entrance and exit forconducting fluid from said passageway to said inner wall of saidinflatable element.

4. A device as defined in claim 3 wherein said means under the controlof said sensing means comprises means for controlling the extent ofopening of said valve means.

5. A device as defined in claim 1 and comprising a tube having a boretherein and wherein said body comprises a core surrounding and securedto said tube, an inflatable sleeve defining said yarn engaging surfaceand having an inner surface surrounding said core, said sleeve beingsealed at the ends thereof, and wherein passageways are provided leadingfrom the bore of said tube through the wall thereof and through saidcore to the inner surface of said sleeve and wherein said means underthe control of said sensing means comprises means for supplying fluidunder pressure to said bore and passageways and means controlling theflow of fluid therethrough.

6. A device as defined in claim 5 wherein said means controlling theflow of fluid through said bore and passageways comprises an exitorifice from said bore, a valve member movable between positions inwhich it closes and opens said exit orifice and wherein said sensingmeans comprises an arm under the control of the tension of the yarnbetween said device and said apparatus, said arm being mounted forswinging movement and including means to adjust said valve towardorifice closing position upon increase of the tension of said yarn.

7. A device for positively delivering yarn from a supply thereof to theknitting instrumentalities of a circular knitting machine having arotary needle cylinder, a rotatable body comprising an inflatable sleevehaving an annular yarn engaging surface, means for rotating said body intimed relationship to the rotation of said needle cylinder, means forguiding yarn from said supply around said yarn engaging surface and tosaid knitting instrumentalities, means engageable with said yarn betweensaid body and said knitting instrumentalities for sensing the tension inthe yarn, and means under the control of said sensing means comprisingmeans for applying fluid under varying pressures to the interior surfaceof said sleeve for varying the circumference thereof at said annularyarn engaging surface.

8. A device as defined in claim 7 wherein said rotatable bodyadditionally comprises a core which said sleeve surrounds, and saidmeans for rotating said body comprises a tube axially penetrating saidcore and secured thereto, and said means for applying fluid undervarying pressure to the interior of said sleeve comprises a supply offluid under pressure connected to the interior of said tube andpassageways leading from the tube to the interior surface of saidsleeve.

9. A device as defined in claim 7 wherein said means under the controlof said sensing means comprising means for applying'fluid under varyingpressure to the interior surface of said sleeve comprises a source offluid under pressure, a passageway leading from said source to theinterior surface of said sleeve, and valve means under the control ofsaid sensing means for varying the fluid pressure within saidpassageway.

I References Cited UNITED STATES PATENTS OTHER REFERENCES B 26081VII/54b, Aug. 23, 1956, German printed application, Janssen.

ROBERT R. MACKEY, Primary Examiner.

